The idea of offering celery as a Valentine's Day gift to your loved one instead of chocolate might send the wrong message, but scientists working to improve the rose genome could make the low-calorie stem a popular Feb. 14 present after all. 
It turns out that one particular gene from celery — the one that controls the enzyme mannitol dehydrogenase — greatly improves the life and quality of rose petals when that gene is spliced into the rose genome. So in an effort to help you get more value from your Valentine's Day gifts, North Carolina State horticultural scientists Dr. John Dole and Dr. John Williamson are leading an effort to insert that gene into roses to create a new superflower less prone to wilt and more resistant to disease, according to PhysOrg.com
"This gene is naturally found in many plants, but it's uncertain whether the rose already has it," said Williamson. "If it does, it doesn't produce enough enzyme to help the plant fight against petal blight."
Petal blight, or botrytis, is a common post-harvest disease in roses that produces wilty, mushy petals. It's caused by invading fungal pathogens that break down the flower's defenses by producing a sugar alcohol called mannitol. Plants that produce enough mannitol dehydrogenase enzyme, like celery, can better break down this sugar alcohol and thus maintain their form for longer.
Roses that contain the celery gene don't smell any different than normal roses, according to the N.C. State researchers. The only noticeable difference between normal roses and these superflowers should be their vase life.
The research is part of a larger effort by Dole and Williamson to build a better rose. Besides implanting the celery gene, the researchers are also examining the types of sugars best suited for mixture with water to keep the plants thriving after they've been harvested. They are even studying how variance in water quality across the country affects the life expectancy of cut roses.
The ultimate goal, according to Dole, is to get roses to survive for up to three to four weeks after they've been harvested. If they succeed, before long your loved one may be able to cherish her Valentine's Day gift well into spring.